Past history, current practice, tax return treatment are all a part of the picture you paint. 

It is also highly unlikely that the pipe would have frozen anyway (if you had the heat on) because there would have been a history of burst pipes in your unit.Not sure why someone would run an AC in the winter.

I don't want to put my kids in public school; I want to teach them myself, the way I learned.

They normally want to see a history of real estate investing.

If your history on your current 4plex is good that should really help.

My 2 unit has a history of rental income, her 2 bedroom cape is where we currently reside and will be moving from and renting out.  

Hell, I went to engineering school and I feel like I learn more on here than I did in school!

It has a great school system and is one of the areas in the metro with the highest demand. 

I'm looking for SFRs in the Chicago area that are in B locations with good schools. 

One of our goals in moving to this city a few months ago form Springfield, MO is to use my real estate career to help provide housing for veterans, international students and returning missionaries who may have trouble finding housing or getting financing for housing as many are returning with little income and/or little credit history as they have been out of the country and often can't show a stable income.